Turbo350 w/shift kit slamming 2nd gear

[HotRodPC]

I wish I had been folowing this one earlier. I didn't read it all but yeah, my first thought was the accumulator spring deleted and I'd just about bet my life it has a B&M shift improver kit installed as a stage 2 kit where you'd probably really like the Stage 1 a lot. To late for that though with that plate since it's been drilled for the stage 2. And I don't mean be the bearer of the bad news, but just so you know, when that accumulator spring breaks soon, remember you heard it here first. You DID NOT correct the problem. You put a band aid on it, and it's actually common even in OEM form, or at least has been for me, when opening up Th350's you find that spring is broke and the broke piece is going to eventally curl up into the other piece. Just the way it is. What I read of Nick's posts is correct to the best of my recallection and then some, but not sure he mentioned this about that spring being common to break and with that shift kit beating on it, I think it'll be sooner than later. And yep, the detent cable and modulator are moot issue in this case. It's the dual feeding plate and the drilled holes causing the harsh affect. Maybe some nice spring day you might want to drop the valve body and install an OEM plate and replace the 2 check balls that are deleted. I'd imagine Nick or I could send you a plate and check balls if you need them. JUST FYI, I do not clean used parts when I send them. I don't keep a solvent bath set up full time.

 

[Octane]

The shop rebuilt my th350 once.It shifted like you were dumping the clutch at every gear change.Well,they said they could firm up the shifts.Then when you slowed down in 3rd gear it wouldn't shift to 3rd,till you were almost stopped.They fixed it.Back in 1992 they rebuilt them around here for $550-$750 depending on which shop.Curious to know what they screwed up.

 

[NickTransmissions]

Do you do much with fwd transaxle

I've done a few GM FWD transmissions, 4T60s and 4T65Es those are fairly straight forward but not touched anything foreign like Hondas, Toyotas etc...

I wish I had been folowing this one earlier. I didn't read it all but yeah, my first thought was the accumulator spring deleted and I'd just about bet my life it has a B&M shift improver kit installed as a stage 2 kit where you'd probably really like the Stage 1 a lot. To late for that though with that plate since it's been drilled for the stage 2. And I don't mean be the bearer of the bad news, but just so you know, when that accumulator spring breaks soon, remember you heard it here first. You DID NOT correct the problem. You put a band aid on it, and it's actually common even in OEM form, or at least has been for me, when opening up Th350's you find that spring is broke and the broke piece is going to eventally curl up into the other piece. Just the way it is. What I read of Nick's posts is correct to the best of my recallection and then some, but not sure he mentioned this about that spring being common to break and with that shift kit beating on it, I think it'll be sooner than later. And yep, the detent cable and modulator are moot issue in this case. It's the dual feeding plate and the drilled holes causing the harsh affect. Maybe some nice spring day you might want to drop the valve body and install an OEM plate and replace the 2 check balls that are deleted. I'd imagine Nick or I could send you a plate and check balls if you need them. JUST FYI, I do not clean used parts when I send them. I don't keep a solvent bath set up full time.

Yep, I mentioned that it is very common to see the 1-2 acc spring broken; in fact I replace that spring with a brand new one on all TH350s I rebuild proactively, regardless if the pre-existing spring is intact or not...I also cautioned him that he may not be done tuning the trans by simply replacing the 1-2 acc spring and that a new spacer plate, check ball replacement may be needed as well...B&M kits are a complete waste of money, IMO.

 

[AuroraGirl]

I've done a few GM FWD transmissions, 4T60s and 4T65Es those are fairly straight forward but not touched anything foreign like Hondas, Toyotas etc...

Yep, I mentioned that it is very common to see the 1-2 acc spring broken; in fact I replace that spring with a brand new one on all TH350s I rebuild proactively, regardless if the pre-existing spring is intact or not...I also cautioned him that he may not be done tuning the trans by simply replacing the 1-2 acc spring and that a new spacer plate, check ball replacement may be needed as well...B&M kits are a complete waste of money, IMO.

wouldnt it be assumed a rebuild would replace accumulator springs? they break enough under normal use in stock applications i feel like thats... just.. no its wrong and dirty. I refuse to believe it!!! !! LALALALALA! jk lol.

So do like granola

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ever see a wheel bearing fail like this? Splines ripped out of it? Ever see strawberry milkshake but NOT from coolant entering the atf, and ever see granola in your pan after all the fun things

 

[NickTransmissions]

wouldnt it be assumed a rebuild would replace accumulator springs? they break enough under normal use in stock applications i feel like thats... just.. no its wrong and dirty. I refuse to believe it!!! !! LALALALALA! jk lol.

So do like granola

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ever see a wheel bearing fail like this? Splines ripped out of it? Ever see strawberry milkshake but NOT from coolant entering the atf, and ever see granola in your pan after all the fun things

Won't comment on wheel bearings as it's outside the scope of this thread but as far as assuming, it's never a good idea...Always ask your transmission builder exactly what they do to the transmission, even it it means making a checklist and going through line by line.

Too many folks assume x, y, or z when it comes to transmission overhaul then when something goes wrong or they somehow find out their assumptions weren't correct, they're caught way off-guard...

 

[AuroraGirl]

Won't comment on wheel bearings as it's outside the scope of this thread but as far as assuming, it's never a good idea...Always ask your transmission builder exactly what they do to the transmission, even it it means making a checklist and going through line by line.

Too many folks assume x, y, or z when it comes to transmission overhaul then when something goes wrong or they somehow find out their assumptions weren't correct, they're caught way off-guard...

when I work on my th350 in my electra since I dont know the thing to be anything but an 88k mile original no rebuild driven by an old grandpa for 11 years (77 to 88) I feel like im going to drop the pan, fluid, filter. I will probably pull the accumulator covers and replace springs because they are old and its in there "while you are in there" and i can replace the modulator and fix the vacuum line so it stops filling the intake with ATF and hopefully it just works

 

[AuroraGirl]

Won't comment on wheel bearings as it's outside the scope of this thread but as far as assuming, it's never a good idea...Always ask your transmission builder exactly what they do to the transmission, even it it means making a checklist and going through line by line.

Too many folks assume x, y, or z when it comes to transmission overhaul then when something goes wrong or they somehow find out their assumptions weren't correct, they're caught way off-guard...

Also I just showed you that because I figured as a transmission builder and expert you would find such a explosive failure interesting

BTW it stilll moved udner its own power, every gear was a forward gear except R which was park (Bound up) LOL. Still could shift from 1-4 oddly enough..

 

[NickTransmissions]

when I work on my th350 in my electra since I dont know the thing to be anything but an 88k mile original no rebuild driven by an old grandpa for 11 years (77 to 88) I feel like im going to drop the pan, fluid, filter. I will probably pull the accumulator covers and replace springs because they are old and its in there "while you are in there" and i can replace the modulator and fix the vacuum line so it stops filling the intake with ATF and hopefully it just works

If you want to service both accumulators, you'll need to drop the valve body and remove the little 'e' clip holding the 2-3 accumulator in place then compress the spring to install the new piston w/sealing ring...I'd strongly recommend doing so if your trans has a plastic 2-3 accumulator piston as they frequently crack at the e-clip...Install an aluminum piston in it's place...Then remove the 1-2 acc piston cover, swap the spring, replace the sealing rings on the 1-2 acc piston, install a new cover O-ring then reinstall the cover...There will be four check balls behind the spacer plate but shouldn't drop out as long as you keep the rear hold-down plate in place.

 

[AuroraGirl]

If you want to service both accumulators, you'll need to drop the valve body and remove the little 'e' clip holding the 2-3 accumulator in place then compress the spring to install the new piston w/sealing ring...I'd strongly recommend doing so if your trans has a plastic 2-3 accumulator piston as they frequently crack at the e-clip...Install an aluminum piston in it's place...Then remove the 1-2 acc piston cover, swap the spring, replace the sealing rings on the 1-2 acc piston, install a new cover O-ring then reinstall the cover...There will be four check balls behind the spacer plate but shouldn't drop out as long as you keep the rear hold-down plate in place.

is a 1977 BOP th350 going to have plastic ones
Its also behind a buick v8 so probably not a weakling th350 like the i6 got

 

[AuroraGirl]

If you want to service both accumulators, you'll need to drop the valve body and remove the little 'e' clip holding the 2-3 accumulator in place then compress the spring to install the new piston w/sealing ring...I'd strongly recommend doing so if your trans has a plastic 2-3 accumulator piston as they frequently crack at the e-clip...Install an aluminum piston in it's place...Then remove the 1-2 acc piston cover, swap the spring, replace the sealing rings on the 1-2 acc piston, install a new cover O-ring then reinstall the cover...There will be four check balls behind the spacer plate but shouldn't drop out as long as you keep the rear hold-down plate in place.

is this something it would be worth pulling the th350 to do this stuff? ive never pulled a ttrans but i know how heavy a th350 is and If I can manhandle one without a torque converter in it, im sure i can lower one down with a jack easy enough on my own

 

[NickTransmissions]

is this something it would be worth pulling the th350 to do this stuff?

It's up to you but isn't necessary if only doing a service as described in my post above...If you're going to be pulling it you should just overhaul it, esp if it hasn't been gone through before and has more than 100k on it...First drop the pan and see what the fluid and bottom look like...if you see anything alarming, put the pan back on w/a few bolts and yank it out, go through it...Then you can install some needed updates like a 4L60E center support w/low roller and HD int. outer race plus set it up for your specific vehicle, preferred shift feel, timing, etc...

 

[AuroraGirl]

It's up to you but isn't necessary if only doing a service as described in my post above...If you're going to be pulling it you should just overhaul it, esp if it hasn't been gone through before and has more than 100k on it...First drop the pan and see what the fluid and bottom look like...if you see anything alarming, put the pan back on w/a few bolts and yank it out, go through it...Then you can install some needed updates like a 4L60E center support w/low roller and HD int. outer race plus set it up for your specific vehicle, preferred shift feel, timing, etc...

at that point i think id look to put a 4 speed in it (200r4?) but im also likely going to use the th350 for a while if its good since its there and will get good mileage on the highway lol.

But Ill try doing it in the car when I do it and see how it goes. also need a q jet rebuilt and engine work rip

 

[HotRodPC]

I've done a few GM FWD transmissions, 4T60s and 4T65Es those are fairly straight forward but not touched anything foreign like Hondas, Toyotas etc...

Yep, I mentioned that it is very common to see the 1-2 acc spring broken; in fact I replace that spring with a brand new one on all TH350s I rebuild proactively, regardless if the pre-existing spring is intact or not...I also cautioned him that he may not be done tuning the trans by simply replacing the 1-2 acc spring and that a new spacer plate, check ball replacement may be needed as well...B&M kits are a complete waste of money, IMO.

Yep, they are brutal kits. I installed many though. Of course I was building transmissions for street racers back then. They wanted them to hit hard like that. If it didn't chirp both rear tires with the locking diff, then they'd bring it back. They were also warned about the internediate roller and race gear going to break, and yep, they were all repeat customers usually about a year to year and a half later. I had upgraded mine to a hardened race and dogbone sprag but still broke input shafts off smooth at the drum. A hardened shaft was very expensive considering what it was but I ended up doing it. Cost of a B&M vs Trans Go, made the B&M kit cheap being about 1/3 the price. All my customers were budget street racers so B&M got used a lot. The stage 1 kit is fairly mild and works well for an everyday driver.

 

[NickTransmissions]

Yep, they are brutal kits. I installed many though. Of course I was building transmissions for street racers back then. They wanted them to hit hard like that. If it didn't chirp both rear tires with the locking diff, then they'd bring it back. They were also warned about the intermediate roller and race gear going to break, and yep, they were all repeat customers usually about a year to year and a half later. I had upgraded mine to a hardened race and dogbone sprag but still broke input shafts off smooth at the drum. A hardened shaft was very expensive considering what it was but I ended up doing it. Cost of a B&M vs Trans Go, made the B&M kit cheap being about 1/3 the price. All my customers were budget street racers so B&M got used a lot. The stage 1 kit is fairly mild and works well for an everyday driver.

Having a contingent of racing customers is always good for business and if you build trust w/them, do right, etc they won't ever go anywhere else...

I never install the shift kits as you can do pretty much everything the B&M kits call for independently, and largely same for the Transgo stuff as well...Most of those kits dual feed the high clutch through transfer plates but if you dual feed internally, block off the 2-3 accumulator (and 1-2 for real high stall / full race apps) and leave out check balls, you don't need the shift kit itself if the trans is on the bench (though they are good for when the trans is still installed).

 

[MikeB]

Earlier I had asked a question about changing fluid and filter in a TH350 at 10 years/10K miles, even if the trans works great and the fluid is still pink. In return I got a question about the fluid type and modulator age.

Answers are: I don't know the fluid type, and the modulator is much more than 10 years old.